Arizona's first documented
Ruby-throated Hummingbird

Warning! Large files - page may take several minutes to load
over slow connections.

Of all the hummingbirds that breed in the United States, only the Ruby-throated and Buff-bellied have never been recorded in Arizona. The Ruby-throated nests from the Atlantic and Gulf coasts to the edge of the Great Plains in the U.S. and across southern Canada from the maritime provinces to the foothills of the Rocky Mountains in western Alberta. Birds from the western edge of the range presumably travel eastward to join the southward migration through the Central and Mississippi flyways. Though there are fewer records of this species from far outside its "normal" range than there are for most western species, Ruby-throateds have been reported in California, Colorado, New Mexico, and, most recently, Idaho. Black-chinned Hummingbird, an abundant species in southern Arizona from spring through fall, is the Ruby-throated's sister species in the genus Archilochus. The extreme similarity between the female and immature male plumages of the two species increases the likelihood that Ruby-throateds have been overlooked in late summer and early fall among the crowds of Black-chinneds throughout the southern Rocky Mountain Flyway.	*Map based on A Field Guide to Hummingbirds* (Peterson Field Guide Series) by Sheri L. Williamson**
On January 1, 2005, professional birding guide Rich Hoyer was between tours when he noticed a worn female Archilochus, distinguished from Costa's by voice and the graduated widths of the inner primaries, visiting a feeder at his north Tucson residence. Black-chinned would be unusual enough in winter, but this bird seemed inconsistent with that identification in the following respects: underparts unusually pale upperparts bright green, including forecrown tail projects well beyond (worn) wing tips bill straight Photos were circulated and posted to the Web, but positive identification was complicated by wing molt and heavy wear to the tips of the outer primaries. Experienced observers agreed that many features suggested Ruby-throated but were reluctant to make a definitive identification without additional details.
On January 10, SABO naturalist Sheri Williamson and volunteers Bill Taylor and Liz Van Horn attempted to capture the bird for banding and in-hand determination of species. The bird was extremely wary, much more so than several resident Anna's of both sexes. After a narrow escape from one of two traps, she returned to the feeder area but refused to enter either trap. The trapping attempt was abandoned around sunset to give her time to feed before nightfall, in case there were no other feeders in the neighborhood. The traps were left in place, but the feeders were repositioned to be accessible without requiring the bird to enter the trap. The following morning, the bird visited both traps but left without entering. A few minutes later, she returned and, after a few seconds of apparent deliberation, entered the second trap and was captured at approximately 10:10. Her identity was immediately apparent on examination of her primaries (see below), but photos and measurements were taken to document this important record (Arizona's 18th hummingbird species).

The profile above shows the plain, pale throat and straight bill. Bill length was 19.0 mm, slightly longer than average for female Ruby-throated but near the average for female Black-chinned.

Note the graduated width of the fresh, dark inner primaries (P1-6) and the slightly curved, tapering contours of the worn outer primaries (P7-10). Distinctive shapes of the feather tips are also visible here: rounded lobes at the tips of P3-5 and a sharp point on P6 (which is not yet full length).

The view above reveals additional detail of the tip shape of the inner primaries and the narrower width of the outermost primary, P10, compared to the adjacent P9. The lobed and notched "boot-like" tips of the inner primaries are not as exaggerated as in adult male plumage but are more distinctive than in immature female plumage.

P10 is seen here against white paper to bring out detail. The tip is extremely worn, but surprisingly little of the length is missing. The wing chord measured 42 mm, probably 2 mm shorter than its original length. Wear has had little effect on the diagnostic shape of the feather, which is straighter and narrower than in Black-chinned. Also note the width of the outer vane of the feather; in Ruby-throated, it is nearly the same width for its entire length, increasing to only twice or less the width at the feather's midpoint. In Black-chinned, this vane expands significantly toward the tip of the feather, becoming approximately 3 times as wide as near the midpoint.

Above, another view of the spread wing shows more clearly that P10 is narrower than P9 and almost even in width over its length, unlike the broad, club-shaped tip of P10 in Black-chinned.
	Though the relatively intense green iridescence of the forecrown in Ruby-throated is a helpful characteristic for field identification, it's of minor importance when the primaries can be examined in hand. This view shows some green all the way to the base of the bill. In Black-chinned, the forecrown is dull ash gray.

The pointed tip of the outermost tail feather and degree of tail wear along with a completely smooth bill indicates an age of at least 16 months (after second year) rather than the 4 to 9 months that we were expecting (second year). Whether she spent her previous winter(s) in Arizona will never be known, but most individual hummingbirds of the highly migratory species show a strong attachment to particular wintering sites. Perhaps she'll return to Rich's yard next fall to become Arizona's first ever repeat record for Ruby-throated Hummingbird. The tail measurement of 25 mm was slightly below average for Ruby-throated, possibly attributable to wear but near the median for the rather broad ranges of both species.

She was offered and accepted sugar water three times during the banding and documentation process (the first time after weighing) and released at approximately 10:30. Her weight was 2.8 g with a trace of fat, which would be abnormally light for a Black-chinned female but is consistent with a lean female Ruby-throated. Above, she rests in visitor Bob's hand while Rich (at far left) commemorates the event.

Many thanks to Rich Hoyer for his alertness to the possibilities presented by this bird
and for his invaluable support and assistance in documenting this long-awaited record.

For additional details on a similar identification challenge in a different setting,
including in-hand detail photos of Black-chinned, see
Stacy Jon Peterson's excellent documentation and analysis of the first record for Ruby-throated in Idaho.

The public is welcome to observe more common breeding and migrant hummingbirds in hand during
the Southeastern Arizona Bird Observatory's hummingbird banding sessions
at the San Pedro Riparian National Conservation Area.
Banding takes place approximately weekly in April May, July, August, and September.
Check SABO's Calendar of Events for upcoming sessions.

References:

Pyle, P. 1997. Identification Guide to North American Birds. Part I: Columbidae to Ploceidae. Slate Creek Press, Bolinas, CA.

Robinson, T. R., R. R. Sargent, and M. B. Sargent. 1996. Ruby-throated Hummingbird (Archilochus colubris). In The Birds of North America, No. 204. (A. Poole and F, Gill, eds.). The Academy of Natural Sciences, Philadelphia, and The American Ornithologists'Union, Washington, D.C.

Williamson, Sheri L. 2002. A Field Guide to Hummingbirds of North America (Peterson Field Guide Series). Houghton Mifflin Co., Boston.

Photos Copyright 2005 by Rich Hoyer and Sheri Williamson
Use or distribution without the express consent of the photographer is prohibited by international law.

Arizona's first documented Ruby-throated Hummingbird

Many thanks to Rich Hoyer for his alertness to the possibilities presented by this bird and for his invaluable support and assistance in documenting this long-awaited record.

For additional details on a similar identification challenge in a different setting, including in-hand detail photos of Black-chinned, see Stacy Jon Peterson's excellent documentation and analysis of the first record for Ruby-throated in Idaho.

Photos Copyright 2005 by Rich Hoyer and Sheri Williamson Use or distribution without the express consent of the photographer is prohibited by international law.

Southeastern Arizona Bird Observatory

Arizona's first documented
Ruby-throated Hummingbird

Many thanks to Rich Hoyer for his alertness to the possibilities presented by this bird
and for his invaluable support and assistance in documenting this long-awaited record.

For additional details on a similar identification challenge in a different setting,
including in-hand detail photos of Black-chinned, see
Stacy Jon Peterson's excellent documentation and analysis of the first record for Ruby-throated in Idaho.

Photos Copyright 2005 by Rich Hoyer and Sheri Williamson
Use or distribution without the express consent of the photographer is prohibited by international law.